(() => {
    class Person {
        constructor(firstName, lastName, fillNmae) {
            this.firstName = firstName;
            this.lastName = lastName;
            this.fillNmae = fillNmae;
        }
    }

    function showFillName(person) {
        return person.firstName + person.lastName;
    }
    const person = new Person('张三', '李四', '王五');
    console.log(showFillName(person));
})();